| 摘要 |
PURPOSE:To reduce the capacity of switching elements by a method wherein the switching elements are interrupted without stopping the action of an inverter, and the elements are protected from overcurrents and overvoltage. CONSTITUTION:Overcurrents and overvoltage are detected when the overcurrents flow to the load electrodes of switching transistors T1-T6 and overvoltage is applied to the load electrodes due to some abnormality, and the switching transistors T1-T6 are chopped in such a manner that the switching transistors T1-T6 are at OFF forcedly when the detecting value is each upper limit set value or higher, and the switching transistors T1-T6 are at ON again when the detecting value is lower limit set value or lower. Thus, the breaking of the switching transistors T1-T6 due to the flowing of overcurrents and the applying of overvoltage to the transistors can be prevented. |
